By Shauna Mazenes
Ashley Wiley had just turned 41 and was raising four young children when a Stage 3 colorectal cancer diagnosis upended her life completely.
"I didn't have any risk factors," says Ashley, now 42. "I'm active, I eat healthy, I felt well.... Nothing in my brain allowed me to think this was possible."
Colorectal cancer has typically been seen in people over 50. However, an alarming increase in young adults diagnosed with aggressive forms of the disease has forced a shift in discourse.
UHN researchers are trying to understand what could be causing this, looking at everything from diet and obesity to microplastics and gut health.
"Because the exact reasons are still not fully understood, it's important to continue investing in research," says Dr. Enrique Sanz Garcia, a medical oncologist at
Princess Margaret Cancer Centre who specializes in colorectal cancer research.
"This will help us learn more about why this rise is happening and support the development of public‑health policies that may reduce risk — such as promoting access to healthier foods and reducing intake of ultra‑processed foods, which may play a role in colorectal cancer development."
In the meantime, UHN is leading and participating in the development of new treatments for patients with advanced and early-stage diagnoses, including targeted drugs, immunotherapy and less invasive, more effective care regimens.
Doctors are also encouraging patients to be aware of the signs and to have conversations with their providers if they suspect something is wrong.
Symptoms of colorectal cancer can appear in different ways
The only symptom Ashley had at the time of her diagnosis was blood in her stool following her pregnancies. She assumed the bleeding was caused by hemorrhoids, a common post-partum side effect.
It wasn't until she sought treatment for the hemorrhoids that a colonoscopy revealed she also had colorectal cancer.
"My GP said it was almost like we found this by mistake," says Ashley. "My concern is how many other women are out there like me, chalking it up to the normal side effects of having a child."
Dr. Sanz Garcia says colorectal cancer can show up in different ways.
"Some people notice changes in their bowel habits, such as switching between diarrhea and constipation. Others may see blood in their stool," he says. "When the disease is more advanced, symptoms like weight loss, tiredness or a reduced appetite can appear."
However, many people in the early stages don't notice any symptoms at all.
In these cases, the cancer is often found during routine blood tests that show anemia, or through screening tests like the Fecal Immunochemical Test (FIT). FIT tests look for tiny amounts of blood in the stool that aren't visible to the naked eye.
"Doing this test every two years is a reliable way to detect early signs of colorectal cancer or pre‑cancerous lesions," he says. "If the FIT test comes back positive, the next recommended step is colonoscopy."
Within days of her colonoscopy, imaging revealed the cancer had spread to the outer layer of the rectum, a Stage 3 diagnosis. Within weeks, she started radiation at Princess Margaret Cancer Centre, followed by chemotherapy.
Ashley responded well to the treatment and is now undergoing non-operative management, a care regimen that avoids removing the rectum or having to use an ostomy bag.
She returns every three months for imaging to check on her progress.
"I remember the surgeon said, ‘We found a tumour … and we're going to cure it,'" she says. "Those words were really important, even as my world started spinning."
UHN scientists researching new treatments for colorectal cancer
Ashley says the trust she built with her UHN care team is what allows her to live without constant fear of recurrence.
"The professionalism, efficiency and complete care from the surgical, radiation and medical oncology teams have allowed me to relax into what is now a really good quality of life," she says.
"That's why we went through all the treatments — so I could have a full, high‑quality life with my family."
Ashley and her husband, Dave, both avid cyclers, signed up for the
Princess Margaret Cancer Foundation Ride, which takes place in June. It's one of the Foundation's largest fundraising events for cancer research and the largest athletic fundraiser in Canada.
She says the cause is close to her heart.
"The reason I'm in the position I'm in is largely because of research," she says, noting the non-operative approach only became available after recent clinical trials.
"People who had this diagnosis years before me had very different outcomes, and their experiences forged the path my team could take. That's why supporting research feels so important."
UHN researchers are working on advancements in early detection and improving treatments by creating specific drugs for some of the most common colon cancer mutations, such as the KRAS gene.
"KRAS-targeting drugs have shown encouraging activity in some patients, but many new agents are currently being studied for a broader population at centres across Canada, including UHN," says Dr. Sanz Garcia.
"There is hope that these drugs will move into later-stage trials and eventually become part of routine care."
Immunotherapy, an approach that enhances the body's immune response against disease, is currently a standard of care for a subset of patients with a genetic mutation called microsatellite instability or mismatch repair deficiency.
New immunotherapy approaches are also being tested in clinical trials at UHN as a treatment for the majority of colon cancer patients who do not respond well to standard immunotherapies, and will hopefully become an option beyond radiation and chemotherapy.
"Early results are encouraging," says Dr. Sanz Garcia, "and these approaches may play a larger role in the future."
